Process for producing dense absorbent charcoal



L. F. HAWLEY. .PROCESS FOR PRonuclNG DENSE ABSORBENT CHARCOAL.

APPLICAT'N FILED AYR. 3,1919.

Patented J illy 2G, 1921.

mv mw the fo l the UNITED sTATEs PATENT I oFFi LEE F. IEAWLEY, 01.1MADISON, WISCONSIN, ASSIGNOR TO UNITED STATES 0F AMERICA.

PROCESS FOR PRODUCJIN'G DENSE ABS Application nica April 3,

To all whom t may concern:

Be it known that Ll'annv F. HAWLEY, a citizen of the United Statesresiding at Madison, in the county of ane and State yof Wisconsin, haveinvented certain new and useful Improvements in Processes for ProducinDense Absorbent Charcoal, of which lowing is a specification. isinvention relates to an improved 'process of making a ,very dense andhomogeneous charcoal table material.

The product of this invention may be utilized for the absorption ofgases.

Ordinarily, the distillation of wood in the manufacture of,` charcoalhas provided a light porous charcoal. .The density of the resultantcharcoal Ahas always varied with the type of wood used, a very heavydense Wood roviding a charcoal normally more dense t an that made fromthe lighter types of wood. As a result of the present invention it isnow .possible to obtain from the lighter types of wood a charcoal muchmore dense than that heretofore obtained `from the heaviest woods.

lie present invention makes it possible to provide a charcoal having adensity of at leastf.95 when an ordinary. light wood. is used, and adensity of at least 1.05 when this same wood has `been given apreliminary hydrolyzing treatment.

he process comprises the comminution of wood to saw-dust or wood flourandthe compression of this material in molds into solid blocks. Theseblocks are formed under a pressure of at least 30,000 pounds per fromwood or similar vegei square inch. The blocks thus formed are thendistilled and at the same time subjected to a constant and directlyapplied mechanical compression of at least square inch. The unusuallyhigh 'compression during distillation produces lthe dense productdesired. This remarkable result is effected by the mechanicalcompression during distillation and is due in art to the fact thatthereis a stage in t e distillation of the blocks of compressed wood, just asthe wood vis decomposing linto charcoal, when the charcoal is slightlyplastic and a suiiciently great pressure therefore closes the pores andinterstices thereof and forms a homogeneous dense charcoal.

f- The detailed steps in the process'may be carried out as' ldescribedhereinafter. Any

pounds per? Specification of Letters Patent.

RBENT CHARCOL.

Patented July 26, 1921.

191s. serial No. 287,315.

ordinary wood, such as pine is c ut or ground toa dition like saw-dustor birch, maple,l or finely divided conwood iiour. This .comminutedmaterial is then compressed in any suitable mold, not

sure of at of wood shown, under a prestons, 30,000 ounds, forming asolid block having a density of about 1.10.

'I hese blocks or briquets are preferably circular in cross. section andwith smooth iiat ends.

A desirable size is one having a diameter of four inches and a thicknessof three inches. The briquets so made are then placed fac diameter s1briquets.

' tube the b wood.

e to face in a metal tube, havinga ightly greater than that of the Iplaced face to face within the riquets form a rod of compressed Howeverif it is desired t spacethe briquets apart, either to permit the passageof gases or to preserve the identity of the briquets, this may be doneby introducing between the briquets thin sheets of metal of the samediameter ofthe briquets, or smaller than the bore of the tube.

Endwise pressur?J is-applied to the column of briquets.

This press from 100 The tube and its contents ure is constant and mayamount to to 250 pounds vper square inch. are subjected to adistillation temperature'of atleast 300 C.

small ran tinuously maintained. the materi during which treatment thepressure is con- The plastic stage of al during distillation covers onlya ge of temperatures, from about C.7 and .if the distillatin temperatureis carried much above this point it is not necessary,

and often not desirable, to

apply extreme pressure during `the last istillation.

Di'erent pressure for the process may necessarily be adopted for variedconditions.

Fon instance, A with a pressure pounds er inchon the briquetsf'usedprior square inch is necessary during distillation to secure bestresults, but with a pressure during distillation.

250 l poun Likewise, a pressure of ds per square inch maintainedthroughout the. distillation would be too high, and this sustainedpressure would negative l'the advantages obtained by its applica.-

tion -early in the distillation treatment, the charcoal being shattered'and rendered useless. On

the other'- hand, if such a high to distil ation a pressure of 950pounds per formed 1n any suitable machine.

pressure be used only during the first part of the distillation the verybest results may dilute acid, preferably sulfuric acid. and

high pressure steam, about pounds per square inch. the water, sugar andother soluble materials are removed. the remaining material dried andbriqueted and distilled as before. The resulting wood products remainingafter the extraction process is produced in large and commercialquantities in the manufacturing plants engaged in the manufacture ofethyl alcohol from waste wood. If this residue is briqueted and distilled under the conditions of this invention the resultant charcoal isdenser` about 1.05, than that obtained directly from wood by theprocess. y

The process may be conducted in any suitable form of apparatus capableof performing the steps specified. The briquets may be The combineddistillation and compression steps require a rather unusual type ofstructures, a suitable form of which is illustrated in the accompanyingdrawing, in which- Figure'1 is a vertical sectional elevationillustrating the compressionl tube mounted in the distilling chamber,

Fig. 2 is a. sectional view taken on the line 2-2 of Fig. 1,

Fig. 3 is a view taken on the line 3-3 of Fig. l looking in thedirection of the arrow.

Referring in detail to the drawing 1 indicatesthe masonry of the endwalls 'of a distillation furnace, 2 indicates the side walls and 3 thetop of the furnace. The necessary strength 'for the structure is madecertain by the liberal use of metal reinforcing where necessary. Each ofthe end walls have two parallel I-beams 4 positioned vertically andmounted in a concrete base 5. Suitable braces 6 are provided tostrengthen the lower ends of the beams 4 and tie-rods 7 extend from theu per part of the beams 4 to further brace t e structure. The furnace islong and narrow and is adapted to be heated by any type of fuel. Asillustrated, the furnace is constructed to use gas or oil as fuel.Adjacent the lower part of the side walls 2 and spaced along the sidesof thesame are a series of ports or openings 8 adapted to receive burnernozzles. pro]ecti ng from any suitable supply gas' pipe or oil plpe. Theflame and hot gases pass upward and through the outlet openings 9provided in the top 3. Y

The apparatus for 'compressing the briquets during distillation includesa cylindrical meta-1 tube or pipe 10 extending longitudinally of thefurnace and projecting beyond the end walls thereof. This pipe. 10 isnecessarily of heavy metal and in order' to conform with the preferredtype of briquet should have a 5 inch bore. The pipe 10 is positioned andsecurely held in one end wall 1 by the facing clamps 11 which are screwthreaded on the pipelO and which clamp the wall and I-beams. Theoppositeend of the pipe -10 is securely positioned in the opposite endwall butis notclamped to the wall, thus allowing for longitudinalmovement resulting from expansion or contraction of the tube duringheating. Bri quets are. inserted into the bore of the pipe 10 throughthe end opening 12 which is provided with a cover pla-te 13 adapted tobe bolted in place over the end of the pipe 10. Gases and vaporsgenerated during the distillation pass upward and outwardly through thegas outlet passage 14 which is located between the cover yplate 13 andthe end of the furnace. Compression is effected by means of a lunger 15havinga drive rod 16 projecting iieyond he packing gland 17 andextending to a'suitable source oflpower indicated as a worm drive 18.-The plunger 15 is adapted to move slowly within the pipe 10 and tocompress the briquets during the heat treatment. The construction shouldprovide for a drive rod such that the moyement of the piston would bereciprocatory and not rotary as is shown diagrammatically on thedrawings.

It is known that charcoal briquets have been made b compressing fibrouswood blocks and dlstilling the same'under mechanically applied pressure.This pressure however was only sufficient to hold the blocks in closecontact with each other. Certain disclosures have shown that it was oldto exercise compression during distillation.' The present inventionprovides for a change in the nature of the charcoal by tremendouspressure during distillation. The density of 115 the resultant productis due to the combination of specific steps and pressures mentioned.

I claim- A 1. The process of making charcoal hav- 120 ing a. specificgravity of4 at least .95 from wood which comprises comminuting. wood,forming blocks of the comminuted wood, subject-ing the blocks to apressure of at least 30.000 pounds to the square inc-h, and distil- 121iling t-he blocks under a substantially constant directly appliedmechanical pressure of at least 100 pounds per inch. i

2. The process of making a dense and homogeneous charcoal whichcomprises T3( forming blocks by compressing comminuted wood, subjectingthe blocks to a pressure of at least 30,000 pounds per'square inch priorto distillation, and subjecting the locks to a combineddistillingtemperature and to a substantially constant directly appliedmechanical pressure of at least 100 pounds per square inch.

3. The process of making charcoal havf ing a specific gravity of atleast .95 which comprises forming blocks by compressi comminuted wood,subjecting the blocks to a pressure of at least 30,000 square inch priorto heating them, subjecting'the blocks to a combined heat treatment of300 C. and to a directly applied mechanical pressure of at least 250pounds per square inch, and subsequently maintainlng the heat treatmentand a lower pressure.

4. The process of making dense and homogeneous charcoal from Wood whichconsists of comminutingwood, subjecti the comminuted Wood to the actionof s furic acid ,pounds per washing the ma- 4blocks b comand steam underpressure, teria] so treated, forming pressing the remaining comminutemate-i a directly applied constant mechanical pres sure of at least 100pounds per square inch.

-5. The process of making dense and homogeneous charcoal from Wood whichconsists of comminuting the wood to be treated, hydrolyzing thismaterial, formi blocks of theL hydrolyzed material, subjecting theblocks toa pressure of atleast 30,000 to the square inch, and distillinthe blocks under a substantially constant irectly applied mechanicalpressure of at least 100 pounds per inch.

In testimony whereof I have aiiixed my signature.

LEE F. HAW'LEY.

pounds

